Polyvinyl butyral, plasticized materials

The two pottant materials studied in this report are plasticized polyvinyl butyral (plPVB) which is easily available and used in safety glass, and a highly stabilized, peroxide crosslinked ethylene/vinyl acetate (EVA) copolymer containing about 33 weight % vinyl acetate (.7). The outer cover/insulator materials studied include polyvinyl fluoride (PVF) and a butyl aerylate/methyl methacrylate graft copolymer (BAgMMA) both are blown films. 

Ethyl alcohol has been made by the hydration of ethylene (9) since 1930. Like isopropyl alcohol, part of the output is used as a solvent, but most is converted to other oxygenated chemicals. Its most important raw material use is conversion to acetaldehyde by catalytic air oxidation. Acetaldehyde, in turn, is the raw material source of acetic acid, acetic anhydride, pentaerythritol, synthetic n-butyl alcohol (via aldol condensation), butyraldehyde, and other products. Butyraldehyde is the source of butyric acid, polyvinyl butyral resin, and 2-ethylhexanol (octyl alcohol). The last-named eight-carbon alcohol is based on the aldol condensation of butyraldehyde and is used to make the important plasticizer di-2-ethylhexyl phthalate. A few examples of the important reactions of acetaldehyde are as follows ... 

Polyvinyl butyral - A nonvapor or liquid permeable plasticized polymer formulation with additive materials that forms a continuous film from an ethanol solution ( 5 min). 

Butyraldehyde is used mainly as an intermediate in the production of synthetic resins, rubber vulcanization accelerators, solvents, and plasticizers. It reacts with polyvinyl alcohol to form polyvinyl butyral which is used as an interlayer for safety glass as well as for coating fabrics. Isobutyraldehyde is used as a solvent or plasticizer in the plastics industry, or as a raw material in the synthesis of isobutyl alcohol, methacrylic acid, neopentyl glycol, etc. 

Products that have to be stripped from the mold are made of an elastomeric material. If solvent is present it can be volatihzed in an oven after each dipping period. Resins that have been used for dip molding include vinyl copolymers, vinyhdene chloride, polyvinyl butyral, nylon, polyvinyl alcohol or acetal, and modifled acrylics. For rigid products, cellulosic plastics, styrene, and similar resins can be used. 

Vinyl Resins n (1934) According to common chemical nomenclature, all resins and polymers made from monomers containing the vinyl group, H2C=CHX. In the chemical literature, polystyrene, polyolefins, polymethyl methacrylate and many other styrenic, ethenic, and acrylic copolymers are classified as vinyls (Mishra, M. K. M., and Yagci, Y., Handbook of Vinyl Polymerization Marcel Dekker, New York, 1998). In the plastics literature, the above materials are given their own classifications and the term vinyl is restricted to compounds in which X, above, is not H, a hydrocarbon radical, nor an acrylic-type ester. In daily use, the term vinyl plastics refers primarily to Polyvinyl Chloride and its copolymers, and secondarily to the following Polyvinyl Acetal, Polyvinyl Acetate, Polyvinyl Butyral, Polyvinyl Dichloride, Polyvinyl Formal, Polyvinylidene Chloride, Polyisobutylvinyl Ether, and Poly(l-Vinylpyrrolidone). 

Thicker plastics generally need to be blanked at elevated temperature. Acrylic, cellulose acetate, cellulose nitrate, ethyl cellulose, polyethylene, polystyrene, vinyl butyral, and polyvinyl chloride can commonly be blanked. The process is accurate to about 1/64 in. Allowance must also be made for thermal shrinkage when the material has been preheated. 

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